在RF或微波網路的的應用電路中，信號源阻抗必須等於負載的共軛阻抗，即：Rs + jXs = RL – jXL 在這個條件下(In this condition) ，從信號源到負載的傳輸能量達到最大並且可以避免能量從負載反射到信號源。
Figure 1 為RF調諧模擬之等效電路，原理為以網路分析儀等效電路連接待測物(DUT)，並在DUT與網路分析儀中間串接一個調諧電路，透過調整調諧電路，使得DUT與量測系統阻抗達到匹配。 在處理RF系統的實際應用問題時，總會遇到一些非常困難的工作，對各部分級聯電路的不同阻抗進行匹配就是其中之一。由於系統之中的各級電路阻抗往往並不相同，一般情況下，需要進行匹配的電路包括天線與低雜訊放大器(LNA)之間的匹配、功率放大器輸出(RFOUT)與天線之間的匹配、LNA/VCO輸出與混頻器輸入之間的匹配。匹配的目的是為了保證信號或能量有效地從“信號源”傳送到“負載”。
- 河小豚Lv 78 年前最佳解答
Application circuits in the RF or microwave network, conjugate impedance of the signal must be equal to the source impedance load, that is: Rs+jXs=RL – jXL under this condition (In this condition), the energy transfer from signal source to the load reaches the maximum energy from the load and avoid reflections to the signal source.
Equivalent circuit of Figure 1 for the simulation of the RF tuner, the principle of equivalent circuit continuous reception of logging into a network Analyzer (DUT) and the DUT and Network Analyzer thread a tuned circuit in the Middle, through adjusting tuned circuits, DUT and measuring system impedance reaches the match.
When dealing with practical applications of RF system issue, there will always be some very difficult work, on the part of cascaded circuits of different impedance matching is one. Due to the impedance of the circuit at all levels of the system, are not always the same, under normal circumstances, require matching circuit including antennas and low-noise amplifier (LNA), the match between power amplifier output (RFOUT), the match between LNA/VCO and antenna matching between the mixer input and output. Match is designed to ensure the signal or energy effectively from the "source" to the "load".
- 阿昌Lv 78 年前
RF or microwave network in the application circuit, the signal source impedance must be equal to the conjugate of the load impedance, ie: Rs + jXs = RL - jXL in this condition (In this condition), the load from the source to the transmission of energy maximum and reflected energy from the load to avoid the source.
Figure 1 is the equivalent circuit analog RF tuner, the principle is to connect the network analyzer analyte equivalent circuit (DUT), and in the middle of the DUT and connect a network analyzer tuned circuit, by adjusting the tuning circuit, making the impedance of the DUT and the measurement system to match.
In dealing with the practical application of RF system problems, there will always be some very difficult work on the part of the cascade of different impedance matching circuit is one of them. As the systems of the impedance of the circuit is not always the same at all levels, under normal circumstances, the need to match the circuit including the antenna and low noise amplifier (LNA) match between amplifier output (RFOUT) and the matching between the antenna , LNA / VCO output and the matching between the mixer input. The purpose is to ensure matching signal or energy efficiently from a "source" to a "load."